1221240400000 has 96 divisors (see below), whose sum is σ = 3040981185060. Its totient is φ = 488496000000.

The previous prime is 1221240399917. The next prime is 1221240400099. The reversal of 1221240400000 is 40421221.

It can be written as a sum of positive squares in 6 ways, for example, as 554953482304 + 666286917696 = 744952^2 + 816264^2 .

It is a super-2 number, since 2×1221240400000² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1126551 + ... + 1926550.

Almost surely, 2^{1221240400000} is an apocalyptic number.

1221240400000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221240400000 is an abundant number, since it is smaller than the sum of its proper divisors (1819740785060).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221240400000 is an frugal number, since it uses more digits than its factorization.

1221240400000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3053140 (or 3053108 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 1221240400000 its reverse (40421221), we get a palindrome (1221280821221).

The spelling of 1221240400000 in words is "one trillion, two hundred twenty-one billion, two hundred forty million, four hundred thousand".